An image reducing method is known for reducing a great number of pixels in an image through simple sampling or operation sampling to produce an image of a small number of pixels (See Patent Citation 1).
Meanwhile, a displaying apparatus is known which drives the three sub pixels of each pixel independently in its LCD (See Patent Citation 2).
Patent Citation 1: JP (Heisei)10-327402A
Patent Citation 2: JP 2003-228337A
There is a demand, for example, for displaying a medical image recorded with an FPD (flat panel detector) of 4096×3328 pixel type on an LCD of 1600×1200 pixel type.
Using the image reduction method of Patent Citation 1, a medical image of 4096×3328 pixels produced by the FPD is reduced to an image of 1477×1200 which can thus be displayed on the LCD of 1600×1200 pixel type. The number of pixels along the minor axis in the reduced image is set to 1200 because it corresponds to the number of pixels along the minor axis on the LCD. The number of pixels along the major axis in the reduced image is set to 1477 because the aspect ratio of the original image has to be maintained.
Since the original image along either of the major axis and the minor axis is reduced from 2.774 (=4096/1477/1200) pixels to one pixel for the LCD, its resolution will significantly be declined.
More specifically, it is essential for the diagnosis of breast cancer to identify a tiny pathological sign such as calcopherite of not greater than 100 μm. As the pitch of its pixels is generally 70 μm, the FPD has a desired degree of the resolution. However, since the pitch of pixels on LCD is equivalent to 194 (=70*2.774) μm of the pitch of pixels on the FPD, a desired degree of the resolution will hardly be maintained.
Each pixel on the LCD of the monochrome liquid crystal display consists of three sub pixels aligned along the major axis of the LCD. The resolution along the major axis on the LCD can thus be improved by driving independently the three sub pixels such as in the display of Patent Citation 2.
However, while the sub pixels are commonly rectangular in the shape, the image reducing method of Patent Citation 1 of which the shape of the pixels is square or circular fails to maintain the aspect ratio of the original image at the display.